Nail polish, irrespective of its composition, is required to be removed from the surface of finger nails and toe nails without damaging the nail or the health of a person who uses it. Equally important, but not generally stated, is that using the polish should not dry out either the nail or the skin and cuticle surrounding the nail, or the skin of the finger or toe.
At the present time, nail polish typically consists essentially of a polymeric binder resin and pigment referred to as lacquers or enamels; primarily used are nitrates of cellulose, either as a pigment dispersant or as a film-forming binder; also used are acrylic polymers, mainly copolymers of (meth)acrylic acid, (meth)acrylic acid esters and styrene as disclosed in U.S. Pat. No. 6,254,878. The term “(meth)acrylic acid” is used to connote both, unsubstituted acrylic acid and its methyl-substituted derivative.
To remove lacquers and enamels, it is essential that a commercial nail polish remover have good polish-dissolving and removal characteristics, good skin conditioning properties, low volatility, low flammability, and low odor; in addition, the nail polish remover should be easy to clean off the finger nails with soap and water.
Until recently, compositions for removing nail polish have relied upon acetone, ethyl acetate and mixtures of these in which one or the other predominates. Acetone is a flammable and toxic liquid which rapidly evaporates upon exposure to room temperature conditions and emits a characteristic odor not easy to mask. Moreover, acetone is so powerful a solvent as to penetrate skin easily; upon evaporating, acetone dries out the keratin of the nail. Thereafter, acetone leaves a visible residue on the nail which residue is difficult to remove from the cleaned nail. Other solvents typically used in nail polish removers include ethyl acetate, and combinations including ethylene and/or propylene carbonate or diethers and diesters, each of which has several undesirable effects similar to those of acetone. Numerous attempts have been made to develop polish removers that avoid the problems of known removers, but there is still a need for a nail polish remover which is less damaging to skin and cuticles than acetone, and which is formulated mainly from environmentally friendly, easy to use higher fatty acid esters derived from naturally occurring vegetable oils, referred to as “source vegetable oils”, in combination with a lower alkyl ester of lactic acid. By “lower alkyl” is meant that the alkyl group has from 1 to 5 carbon atoms; by “higher fatty acid” is meant that the fatty acid has more than 12 carbon atoms.